There is a colorimetric device that illuminates, using an integrating sphere, a sample disposed at an aperture portion of the integrating sphere as a target of colorimetry, receives reflected light from the sample, and measures a surface color (specifically, an object color) of the sample (e.g., Japanese Patent Application Laid-Open No. 2005-62095).
In this colorimetric device, the size of an aperture for measurement (also referred to as a measurement aperture) of the integrating sphere is determined appropriately in accordance with the type, the size, and the like of the sample. Measurement (average value measurement and spot measurement) is made using a portion of the sample disposed to face the measurement aperture as an area (also referred to as a measured area) as a planar target of measurement. In a portable or handheld colorimetric device, the diameter of the measurement aperture is usually set to approximately 3 mm to 20 mm in accordance with the size of the integrating sphere. This is because the diameter of the measurement aperture is set, relative to the diameter of the integrating sphere, within a range in which measurement of the object color is less likely to be affected.
If two-dimensional distribution of a color in a measured area having a predetermined size can be measured in the colorimetric device, color irregularity and a complicated shape, such as a pattern, in the measured area can be measured through selection of the measured area, simultaneous measurement at a plurality of separate locations and measurement in an elongated area, and the like. Such measurement cannot be achieved in a case where an average value of colors in a circular measured area on the surface of a sample disposed at a circular measurement aperture is measured, as in a conventional colorimetric device.